This invention relates to improvements in and to a liquid transferring device of the type as described and claimed in the U.S. Pat. No. 3,921,859 of the same applicant. The device according to said U.S. patent is particularly adapted for transferring liquids having chemical and/or thermal features of such a nature as to prevent the use of valve means or the like, as in transferring molten metals. Such a device, for transferring liquids contained at a given level in a first container to a second container located at an elevation lower than such given level, comprises, in combination, an inverted U-shaped liquid-transferring siphon pipe, having a rising length and a descending length extending from the bight of its inverted U-shape, positioned while in use with its rising length in said first container and its descending length extending downwardly toward said second container with an outlet end at an elevation below said given level; said rising length communicating with the liquid level in said first container at a liquid inlet opening at a level below said given level; a gas-tightly sealable crucible filling chamber having a bottom inlet in fluid-tight communication with said rising lengths and communicating with said liquid inlet opening; and pneumatic pressure applying means communicating with said crucible filling chamber at its upper end and selectively operable to selectively apply either a negative or a positive pressure controllably to liquid in said siphon pipe to prime said siphon pipe for transfer of liquid from said first container to said second container.